Dieting

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Dieting 

 

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Human body weight

Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. Dieting to lose weight is recommended for people with weight-related health problems, but not otherwise healthy people. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients (low-fat, low-carbohydrate, etc), have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.

The first popular diet was "Banting", named after William Banting. In his 1863 pamphlet, Letter on Corpulence, Addressed to the Public, he outlined the details of a particular low-carbohydrate, low-calorie diet that led to his own dramatic weight loss.

One survey found that almost half of all American adults attempt to lose their weight through dieting.

History

William Banting, popularized one of the first weight loss diets in the 19th century.

According to Foxcroft, the word diet comes from the Greek diaita, which represents a notion of a whole way healthy lifestyle including both mental and physical health, rather than a narrow weight-loss regimen.

One of the first dietitians was the English doctor George Cheyne. He himself was tremendously overweight and would constantly eat large quantities of rich food and drink. He began a meatless diet, taking only milk and vegetables, and soon regained his health. He began publicly recommending his diet for everyone suffering from obesity. In 1724, he wrote An Essay of Health and Long Life, in which he advises exercise and fresh air and avoiding luxury foods.

The Scottish military surgeon, John Rollo, published Notes of a Diabetic Case in 1797. It described the benefits of a meat diet for those suffering from diabetes, basing this recommendation on Matthew Dobson's discovery of glycosuria in diabetes mellitus. By means of Dobson's testing procedure (for glucose in the urine) Rollo worked out a diet that had success for what is now called type 2 diabetes.

The first popular diet was "Banting", named after the English undertaker William Banting. In 1863, he wrote a booklet called Letter on Corpulence, Addressed to the Public, which contained the particular plan for the diet he had successfully followed. His own diet was four meals per day, consisting of meat, greens, fruits, and dry wine. The emphasis was on avoiding sugar, sweet foods, starch, beer, milk and butter. Banting's pamphlet was popular for years to come, and would be used as a model for modern diets. The pamphlet's popularity was such that the question "Do you bant?" referred to his method, and eventually to dieting in general. His booklet remains in print as of 2007.

The first weight-loss book to promote calorie counting, and the first weight-loss book to become a bestseller, was the 1918 Diet and Health: With Key to the Calories by American physician and columnist Lulu Hunt Peters.

It was estimated that over 1000 weight loss diets have been developed up to 2014.

Types

Main article: List of diets

A restricted diet is more often pursued by those who want to lose weight. Some people follow a diet to gain weight (usually in the form of muscle). Diets can also be used to maintain a stable body weight and improve health.

Low-fat

Main article: Low-fat diet

Low-fat diets involve the reduction of the percentage of fat in one's diet. Calorie consumption is reduced because less fat is consumed. Diets of this type include NCEP Step I and II. A meta-analysis of 16 trials of 2–12 months' duration found that low-fat diets (without intentional restriction of caloric intake) resulted in average weight loss of 3.2 kg (7.1 lb) over habitual eating.

A low-fat, plant-based diet has been found to improve control of weight, blood sugar levels, and cardiovascular health.

Low-carbohydrate

Main article: Low-carbohydrate diet

Low-carbohydrate diets are relatively high in protein and fats. Low-carbohydrate diets are sometimes ketogenic (i.e., they restrict carbohydrate intake sufficiently to cause ketosis).

"The glycemic index (GI) factor is a ranking of foods based on their overall effect on blood sugar levels. The diet based around this research is called the Low GI diet. Low glycemic index foods, such as lentils, provide a slower, more consistent source of glucose to the bloodstream, thereby stimulating less insulin release than high glycemic index foods, such as white bread."

A randomized controlled trial comparing four diets concluded that the high-carbohydrate, low-glycemic index diet was the most favorable as it led to both high weight loss and a decline in low density lipoprotein.

The "glycemic load" is the glycemic index multiplied by the amount of carbohydrate. A meta-analysis by the Cochrane Collaboration concluded that low glycemic index or low glycemic load diets led to more weight loss and better lipid profiles but did not separate the effects of the load versus the index.

Low-calorie

Main article: Calorie restriction

Low-calorie diets usually produce an energy deficit of 500–1,000 calories per day, which can result in a 0.5 to 1 kilogram (1.1 to 2.2 pounds) weight loss per week. One of the most commonly used low-calorie diets is Weight Watchers. The National Institutes of Health reviewed 34 randomized controlled trials to determine the effectiveness of low-calorie diets. They found that these diets lowered total body mass by 8% in the short term, over 3–12 months. Women doing low-calorie diets should have at least 1,000 calories per day and men should have approximately 1,200 calories per day. These caloric intake values vary depending on additional factors, such as age and weight.

Very low-calorie

Main article: Very low calorie diet

Very low calorie diets provide 200–800 calories per day, maintaining protein intake but limiting calories from both fat and carbohydrates. They subject the body to starvation and produce an average loss of 1.5–2.5 kg (3.3–5.5 lb) per week. "2-4-6-8", a popular diet of this variety, follows a four-day cycle in which only 200 calories are consumed the first day, 400 the second day, 600 the third day, 800 the fourth day, and then totally fasting, after which the cycle repeats. There is some evidence that these diets results in considerable weight loss. These diets are not recommended for general use and should be reserved for the management of obesity as they are associated with adverse side effects such as loss of lean muscle mass, increased risks of gout, and electrolyte imbalances. People attempting these diets must be monitored closely by a physician to prevent complications.

The concept of crash dieting is to drastically reduce calories, using a very-low-calorie diet. Crash dieting can be highly dangerous because it can cause various kind of issues for the human body. Crash dieting can produce weight loss but without professional supervision all along, the extreme reduction in calories and potential unbalance in the diet's composition can lead to detrimental effects, including sudden death.

Fasting

Main articles: Fasting and Intermittent fasting

Fasting is when there is a long time interval between the meals. In dieting, long term (periodic) fasting is not recommended, instead, having small portions of food after small intervals is encouraged. Lengthy fasting can also be dangerous due to the risk of malnutrition and should be carried out only under medical supervision. During prolonged fasting or very low calorie diets the reduction of blood glucose, the preferred energy source of the brain, causes the body to deplete its glycogen stores. Once glycogen is depleted the body begins to fuel the brain using ketones, while also metabolizing body protein (including but not limited to skeletal muscle) to be used to synthesize sugars for use as energy by the rest of the body. Most experts believe that a prolonged fast can lead to muscle wasting, although some dispute this. The use of short-term fasting, or various forms of intermittent fasting, have been used as a form of dieting to circumvent the issues of long fasting.

Detox

Main article: Detox diet

Detox diets are promoted with unsubstantiated claims that they can eliminate "toxins" from the human body. Many of these diets use herbs or celery and other juicy low-calorie vegetables.

Environmentally sustainable

See also: Environmental vegetarianism

Another kind of diet focuses not on the dieter's health effects, but on its environment. The One Blue Dot plan of the BDA offers recommendations towards reducing diets' environmental impacts, by:

1. Reducing meat to 70g per person per day.
2. Prioritising plant proteins.
3. Promoting fish from sustainable sources.
4. Moderate dairy consumption.
5. Focusing on wholegrain starchy foods.
6. Promoting seasonal locally sourced fruits and vegetables.
7. Reducing high fat, sugar and salty foods overconsumption.
8. Promoting tap water and unsweetened tea/coffee as the de facto choice for healthy hydration.
9. Reducing food waste.

Effectiveness

Several diets are effective for weight loss of obese individuals, with diet success most predicted by adherence and little effect resulting from the type or brand of diet. As weight maintenance depends on calorie intake, diets emphasising certain macronutrients (low-fat, low-carbohydrate, etc.) have been shown to be no more effective than one another and no more effective than diets that maintain a typical mix of foods with smaller portions and perhaps some substitutions (e.g. low-fat milk, or less salad dressing). A meta-analysis of six randomized controlled trials found no difference between low-calorie, low-carbohydrate, and low-fat diets, with a 2–4 kilogram weight loss over 12–18 months in all studies. Extreme diets may, in some cases, lead to malnutrition.

A major challenge regarding weight loss and dieting relates to compliance. While dieting can effectively promote weight loss in the short term, the intervention is hard to maintain over time and suppresses skeletal muscle thermogenesis. Suppressed thermogenesis accelerates weight regain once the diet stops, unless that phase is accompanied by a well-timed exercise intervention, as described by the Summermatter cycle.

On average, short-term dieting results in a meaningful long-term weight-loss, although more limited because of gradual 1 to 2 kg/year weight regain. For each individual, the results will be different, with some even regaining more weight than they lost, while a few others achieve a tremendous loss, so that the "average weight loss" of a diet is not indicative of the results other dieters may achieve. A 2001 meta-analysis of 29 American studies found that participants of structured weight-loss programs maintained an average of 23% (3 kg) of their initial weight loss after five years, representing an sustained 3.2% reduction in body mass.

Dieting appears more effective than exercise for weight loss, but combining both provides even greater long-term results.

Adverse Effects

Increased Mortality Rate

A number of studies have found that intentional weight loss is associated with an increase in mortality in people without weight-related health problems. A 2009 meta-analysis of 26 studies found that "intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors), especially unhealthy obese, but appeared to be associated with slightly increased mortality for healthy individuals, and for those who were overweight but not obese."

Dietary Supplements

Due to extreme or unbalanced diets, dietary supplements may be needed. They are able to provide the vitamins, minerals, herbs or other supplements that may be missing from an unbalanced diet. While they could be very helpful to maintain a healthy lifestyle with an unbalanced diet, supplements are medications that can't be overused. Overdosing on any dietary supplement can cause a range of side effects depending on which supplement was taken.

Eating disorders

In an editorial for Psychological Medicine, George Hsu concludes that dieting is likely to lead to the development of an eating disorder in the presence of certain risk factors. A 2006 study found that dieting and unhealthy weight-control behaviors were predictive of obesity and eating disorders five years later, with the authors recommending a "shift away from dieting and drastic weight-control measures toward the long-term implementation of healthful eating and physical activity".

Mechanism

When the body is expending more energy than it is consuming (e.g. when exercising), the body's cells rely on internally stored energy sources, such as complex carbohydrates and fats, for energy. The first source to which the body turns is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate, 65% of which is stored in skeletal muscles and the remainder in the liver (totaling about 2,000 kcal in the whole body). It is created from the excess of ingested macronutrients, mainly carbohydrates. When glycogen is nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to generate energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.

Set-Point Theory

See also: Energy homeostasis § Imbalance

The Set-Point Theory, first introduced in 1953, postulated that each body has a preprogrammed fixed weight, with regulatory mechanisms to compensate. This theory was quickly adopted and used to explain failures in developing effective and sustained weight loss procedures. A 2019 systematic review of multiple weight change procedures, including alternate day fasting and time-restricted feeding but also exercise and overeating, found systematic "energetic errors" for all these procedures. This shows that the body cannot precisely compensate for errors in energy/calorie intake, countering the Set-Point Theory and potentially explaining both weight loss and weight gain such as obesity. This review was conducted on short-term studies, therefore such a mechanism cannot be excluded in the long term, as evidence is currently lacking on this timeframe.

Methods

Meals timing

Meals timing schedule is known to be an important factor of any diet. Recent evidence suggest that new scheduling strategies, such as intermittent fasting or skipping meals, and strategically placed snacks before meals, may be recommendable to reduce cardiovascular risks as part of a broader lifestyle and dietary change.

Food diary

A 2008 study published in the American Journal of Preventive Medicine showed that dieters who kept a daily food diary (or diet journal), lost twice as much weight as those who did not keep a food log, suggesting that if a person records their eating, they are more aware of what they consume and therefore eat fewer calories.

Water

Main article: Weight loss effects of water

A 2009 review found limited evidence suggesting that encouraging water consumption and substituting energy-free beverages for energy-containing beverages (i.e., reducing caloric intake) may facilitate weight management. A 2009 article found that drinking 500 ml of water prior to meals for a 12-week period resulted in increased long-term weight reduction. (References given in main article.)

Society

It is estimated that about 1 out of 3 Americans is dieting at any given time. 85% of dieters are women. Approximately sixty billion dollars are spent every year in the USA on diet products, including "diet foods," such as light sodas, gym memberships or specific regimes. 80% of dieters start by themselves, whereas 20% see a professional or join a paid program. The typical dieter attempts 4 tries per year.

Weight loss groups

Some weight loss groups aim to make money, others work as charities. The former include Weight Watchers and Peertrainer. The latter include Overeaters Anonymous, TOPS Club and groups run by local organizations.

These organizations' customs and practices differ widely. Some groups are modelled on twelve-step programs, while others are quite informal. Some groups advocate certain prepared foods or special menus, while others train dieters to make healthy choices from restaurant menus and while grocery-shopping and cooking.

Orthorexia nervosa

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Orthorexia_nervosa 

Orthorexia nervosa /ˌɔːrθəˈrɛksiə nɜːrˈvoʊsə/ (also known as orthorexia) (ON) is a proposed eating disorder characterized by an excessive preoccupation with eating healthy food. The term was introduced in 1997 by American physician Steven Bratman, M.D. He suggested that some people's dietary restrictions intended to promote health may paradoxically lead to unhealthy consequences, such as social isolation, anxiety, loss of ability to eat in a natural, intuitive manner, reduced interest in the full range of other healthy human activities, and, in rare cases, severe malnutrition or even death.

In 2009, Ursula Philpot, chair of the British Dietetic Association and senior lecturer at Leeds Metropolitan University, described people with orthorexia nervosa as being "solely concerned with the quality of the food they put in their bodies, refining and restricting their diets according to their personal understanding of which foods are truly 'pure'." This differs from other eating disorders, such as anorexia nervosa and bulimia nervosa, where those affected focus on the quantity of food eaten.

Orthorexia nervosa also differs from anorexia nervosa in that it does not disproportionally affect one gender. Studies have found that orthorexia nervosa is equally found in both men and women with no significant gender differences at all. Furthermore, research has found significant positive correlations between ON and both narcissism and perfectionism, but no significant correlation between ON and self esteem. This shows that high-ON individuals likely take pride over their healthy eating habits over others and that is the driving force behind their orthorexia as opposed to body image like anorexia.

Orthorexia nervosa is not recognized as an eating disorder by the American Psychiatric Association, and so is not mentioned as an official diagnosis in the widely used Diagnostic and Statistical Manual of Mental Disorders (DSM).

Signs and symptoms

Symptoms of orthorexia nervosa include "obsessive focus on food choice, planning, purchase, preparation, and consumption; food regarded primarily as source of health rather than pleasure; distress or disgust when in proximity to prohibited foods; exaggerated faith that inclusion or elimination of particular kinds of food can prevent or cure disease or affect daily well-being; periodic shifts in dietary beliefs while other processes persist unchanged; moral judgment of others based on dietary choices; body image distortion around sense of physical "impurity" rather than weight; persistent belief that dietary practices are health-promoting despite evidence of malnutrition."

Cause

There has been no investigation into whether there may be a biological cause specific to orthorexia nervosa. It may be a food-centered manifestation of obsessive-compulsive disorder, which has a lot to do with control.

Diagnosis

In 2016, formal criteria for orthorexia were proposed in the peer-reviewed journal Eating Behaviors by Thom Dunn and Steven Bratman. These criteria are as follows:

Criterion A. Obsessive focus on "healthy" eating, as defined by a dietary theory or set of beliefs whose specific details may vary; marked by exaggerated emotional distress in relationship to food choices perceived as unhealthy; weight loss may ensue, but this is conceptualized as an aspect of ideal health rather than as the primary goal. As evidenced by the following:

1. Compulsive behavior and/or mental preoccupation regarding affirmative and restrictive dietary practices believed by the individual to promote optimum health. (Footnotes to this criteria add: Dietary practices may include use of concentrated "food supplements." Exercise performance and/or fit body image may be regarded as an aspect or indicator of health.)
2. Violation of self-imposed dietary rules causes exaggerated fear of disease, sense of personal impurity and/or negative physical sensations, accompanied by anxiety and shame.
3. Dietary restrictions escalate over time, and may come to include elimination of entire food groups and involve progressively more frequent and/or severe "cleanses" (partial fasts) regarded as purifying or detoxifying. This escalation commonly leads to weight loss, but the desire to lose weight is absent, hidden or subordinated to ideation about healthy food.

Criterion B. The compulsive behavior and mental preoccupation becomes clinically impairing by any of the following:

1. Malnutrition, severe weight loss or other medical complications from restricted diet
2. Intrapersonal distress or impairment of social, academic or vocational functioning secondary to beliefs or behaviors about healthy diet
3. Positive body image, self-worth, identity and/or satisfaction excessively dependent on compliance with self-defined "healthy" eating behavior.

A diagnostic questionnaire has been developed for orthorexia sufferers, similar to questionnaires for other eating disorders, named the ORTO-15. However, Dunn and Bratman critique this survey tool as lacking appropriate internal and external validation.

Epidemiology

Results across scientific findings have yet to find a definitive conclusion to support whether nutrition students and professionals are at higher risk than other population subgroups, due to differing results in the research literature. There are only a few notable scientific works that, in an attempt to explore the breadth and depth of the still vaguely-understood illness, have tried to identify which groups in society are most vulnerable to its onset. This includes a 2008 German study, which based its research on the widespread suspicion that the most nutritionally-informed, such as university nutrition students, are a potential high-risk group for eating disorders, due to a substantial accumulation of knowledge on food and its relationship to health; the idea being that the more one knows about health, the more likely an unhealthy fixation about being healthy can develop. This study also inferred that orthorexic tendencies may even fuel a desire to study the science, indicating that many within this field might suffer from the disorder before commencing the course. However the results found that the students in the study, upon initial embarkation of their degree, did not have higher orthorexic values than other non-nutrition university students, and thus the report concluded that further research is needed to clarify the relationship between food-education and the onset of ON.

Similarly, in a Portuguese study on nutrition tertiary students, the participants' orthorexic scores (according to the ORTO-15 diagnostic questionnaire) actually decreased as they progressed through their course, as well as the overall risk of developing an eating disorder being an insignificant 4.2 percent. The participants also answered questionnaires to provide insight into their eating behaviours and attitudes, and despite this study finding that nutrition and health-science students tend to have more restrictive eating behaviours, these studies however found no evidence to support that these students have "more disturbed or disordered eating patterns than other students" These two aforementioned studies conclude that the more understanding of food one has is not necessarily a risk factor for ON, explaining that the data gathered suggests dietetics professionals are not at significant risk of it.

However, these epidemiologic studies have been critiqued as using a fundamentally flawed survey tool that inflates prevalence rates. Scholars have questioned both the reliability and validity of the ORTO-15.

Most scientific findings tend to agree, however, young adults and adolescents are extremely susceptible to developing eating disorders. One study found that there was no relationship between BOT score and college major, which may indicate the prevalence of mental health issues and eating disorders on college campuses and that health and science majors are no longer the only ones affected More studies have also been conducted on the link between increased Instagram use and Orthorexia nervosa. The social media based healthy community has recently grown in popularity especially on platforms such as Instagram. The hashtag #food is one of the top 25 most popular hashtags on Instagram. A study that investigated this relationship found that increased use of Instagram correlated between symptoms of ON with no other social media platform having the same effect. With young adults and adolescents making up the majority of social media users, exposure to this type of content can lead to developing unhealthy behavior.

History

In a 1997 article in the magazine Yoga Journal, the American physician Steven Bratman coined the term "orthorexia nervosa" from the Greek ορθο- (ortho, "right" or "correct"), and όρεξις (orexis, "appetite"), literally meaning 'correct appetite', but in practice meaning 'correct diet'. The term is modeled on anorexia, literally meaning "without appetite", as used in the definition of the condition anorexia nervosa. (In both terms, "nervosa" indicates an unhealthy psychological state.) Bratman described orthorexia as an unhealthy fixation with what the individual considers to be healthy eating. Beliefs about what constitutes healthy eating commonly originate in one or another dietary theory such as raw foods veganism or macrobiotics, but are then taken to extremes, leading to disordered eating patterns and psychological and/or physical impairment. Bratman based this proposed condition on his personal experiences in the 1970s, as well as behaviors he observed among his patients in the 1990s. In 2000, Bratman, with David Knight, authored the book Health Food Junkies, which further expanded on the subject.

Following the publication of the book, in 2004 a team of Italian researchers from La Sapienza University of Rome, published the first empirical study attempting to develop a tool to measure the prevalence of orthorexia, known as the ORTO-15.

In 2015, responding to news articles in which the term orthorexia is applied to people who merely follow a non-mainstream theory of healthy eating, Bratman specified the following: "A theory may be conventional or unconventional, extreme or lax, sensible or totally wacky, but, regardless of the details, followers of the theory do not necessarily have orthorexia. They are simply adherents of a dietary theory. The term 'orthorexia' only applies when an eating disorder develops around that theory." Bratman elsewhere clarifies that with a few exceptions, most common theories of healthy eating are followed safely by the majority of their adherents; however, "for some people, going down the path of a restrictive diet in search of health may escalate into dietary perfectionism." Karin Kratina, PhD, writing for the National Eating Disorders Association, summarizes this process as follows: "Eventually food choices become so restrictive, in both variety and calories, that health suffers – an ironic twist for a person so completely dedicated to healthy eating."

Although orthorexia is not recognized as a mental disorder by the American Psychiatric Association, and it is not listed in the DSM-5, as of January 2016, four case reports and more than 40 other articles on the subject have been published in a variety of peer-reviewed journals internationally. According to a study published in 2011, two-thirds of a sample of 111 Dutch-speaking eating disorder specialists felt they had observed the syndrome in their clinical practice.

According to the Macmillan English Dictionary, the word is entering the English lexicon. The concept of orthorexia as a newly developing eating disorder has attracted significant media attention in the 21st century.

Orthorexia and other disorders

Orthorexia differs from anorexia and bulimia in its relationship to food. Instead of focusing on food intake in an attempt to lose weight and eat less, orthorexia is an "obsession about the quality of food intake" and is fueled by a feeling of achieving perfection and purity by only consuming "healthy" foods.

Orthorexic behaviors can often lead to malnutrition and weight loss, and it is often associated with anorexia nervosa. Studies have also shown that obsessive-compulsive tendencies are linked to the development of orthorexia, and some researchers suggest that orthorexia should be diagnosed as OCD because it is driven by an obsession for attaining a perfect diet.

Heuristic

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Heuristic

A heuristic (/hjʊˈrɪstɪk/; from Ancient Greek εὑρίσκω (heurískō) 'I find, discover'), or heuristic technique, is any approach to problem solving or self-discovery that employs a practical method that is not guaranteed to be optimal, perfect, or rational, but is nevertheless sufficient for reaching an immediate, short-term goal or approximation. Where finding an optimal solution is impossible or impractical, heuristic methods can be used to speed up the process of finding a satisfactory solution. Heuristics can be mental shortcuts that ease the cognitive load of making a decision.

Examples that employ heuristics include using trial and error, a rule of thumb or an educated guess.

Overview

Heuristics are the strategies derived from previous experiences with similar problems. These strategies depend on using readily accessible, though loosely applicable, information to control problem solving in human beings, machines and abstract issues. When an individual applies a heuristic in practice, it generally performs as expected. However it can alternatively create systematic errors.

The most fundamental heuristic is trial and error, which can be used in everything from matching nuts and bolts to finding the values of variables in algebra problems. In mathematics, some common heuristics involve the use of visual representations, additional assumptions, forward/backward reasoning and simplification. Here are a few commonly used heuristics from George Pólya's 1945 book, How to Solve It:

• If you are having difficulty understanding a problem, try drawing a picture.
• If you can't find a solution, try assuming that you have a solution and seeing what you can derive from that ("working backward").
• If the problem is abstract, try examining a concrete example.
• Try solving a more general problem first (the "inventor's paradox": the more ambitious plan may have more chances of success).

In psychology, heuristics are simple, efficient rules, learned or inculcated by evolutionary processes, that have been proposed to explain how people make decisions, come to judgements, and solve problems typically when facing complex problems or incomplete information. Researchers test if people use those rules with various methods. These rules work well under most circumstances, but in certain cases can lead to systematic errors or cognitive biases.

History

The study of heuristics in human decision-making was developed in the 1970s and the 1980s by the psychologists Amos Tversky and Daniel Kahneman although the concept had been originally introduced by the Nobel laureate Herbert A. Simon, whose original, primary object of research was problem solving that showed that we operate within what he calls bounded rationality. He coined the term satisficing, which denotes a situation in which people seek solutions, or accept choices or judgements, that are "good enough" for their purposes although they could be optimised.

Rudolf Groner analysed the history of heuristics from its roots in ancient Greece up to contemporary work in cognitive psychology and artificial intelligence, proposing a cognitive style "heuristic versus algorithmic thinking", which can be assessed by means of a validated questionnaire.

Adaptive toolbox

Gerd Gigerenzer and his research group argued that models of heuristics need to be formal to allow for predictions of behavior that can be tested. They study the fast and frugal heuristics in the "adaptive toolbox" of individuals or institutions, and the ecological rationality of these heuristics; that is, the conditions under which a given heuristic is likely to be successful. The descriptive study of the "adaptive toolbox" is done by observation and experiment, the prescriptive study of the ecological rationality requires mathematical analysis and computer simulation. Heuristics – such as the recognition heuristic, the take-the-best heuristic and fast-and-frugal trees – have been shown to be effective in predictions, particularly in situations of uncertainty. It is often said that heuristics trade accuracy for effort but this is only the case in situations of risk. Risk refers to situations where all possible actions, their outcomes and probabilities are known. In the absence of this information, that is under uncertainty, heuristics can achieve higher accuracy with lower effort. This finding, known as a less-is-more effect, would not have been found without formal models. The valuable insight of this program is that heuristics are effective not despite their simplicity — but because of it. Furthermore, Gigerenzer and Wolfgang Gaissmaier found that both individuals and organisations rely on heuristics in an adaptive way.

Cognitive-experiential self-theory

Heuristics, through greater refinement and research, have begun to be applied to other theories, or be explained by them. For example, the cognitive-experiential self-theory (CEST) also is an adaptive view of heuristic processing. CEST breaks down two systems that process information. At some times, roughly speaking, individuals consider issues rationally, systematically, logically, deliberately, effortfully and verbally. On other occasions, individuals consider issues intuitively, effortlessly, globally, and emotionally. From this perspective, heuristics are part of a larger experiential processing system that is often adaptive, but vulnerable to error in situations that require logical analysis.

Attribute substitution

In 2002, Daniel Kahneman and Shane Frederick proposed that cognitive heuristics work by a process called attribute substitution, which happens without conscious awareness. According to this theory, when somebody makes a judgement (of a "target attribute") that is computationally complex, a more easily calculated "heuristic attribute" is substituted. In effect, a cognitively difficult problem is dealt with by answering a rather simpler problem, without being aware of this happening. This theory explains cases where judgements fail to show regression toward the mean. Heuristics can be considered to reduce the complexity of clinical judgments in health care.

Psychology

Informal models of heuristics

Main article: Heuristics in judgment and decision making

• Affect heuristic — Mental shortcut which uses emotion to influence the decision. Emotion is the effect that plays the lead role that makes the decision or solves the problem quickly or efficiently. It is used while judging the risks and benefits of something, depending on the positive or negative feelings that people associate with a stimulus. It can also be considered the gut decision since if the gut feeling is right, then the benefits are high and the risks are low.

• Anchoring and adjustment — Describes the common human tendency to rely more heavily on the first piece of information offered (the "anchor") when making decisions. For example, in a study done with children, the children were told to estimate the number of jellybeans in a jar. Groups of children were given either a high or low "base" number (anchor). Children estimated the number of jellybeans to be closer to the anchor number that they were given.

• Availability heuristic — A mental shortcut that occurs when people make judgements about the probability of events by the ease with which examples come to mind. For example, in a 1973 Tversky & Kahneman experiment, the majority of participants reported that there were more words in the English language that start with the letter K than for which K was the third letter. There are actually twice as many words in the English Language that have K as the third letter as those that start with K, but words that start with K are much easier to recall and bring to mind.

• Balance Heuristic — Applies to when an individual balances the negative and positive effects from a decision which makes the choice obvious.

• Base Rate Heuristic — When a decision involves probability this is a mental shortcut that uses relevant data to determine the probability of an outcome occurring. When using this Heuristic there is a common issue where individuals misjudge the likelihood of a situation. For example, if there is a test for a disease which has an accuracy of 90%, people may think it’s a 90% they have the disease even though the disease only affects 1 in 500 people. 

• Common Sense Heuristic --- Used frequently by individuals when the potential outcomes of a decision appear obvious. For example, when your television remote goes flat, you would change the batteries.

• Contagion heuristic — follows the Law of Contagion or Similarity. This leads people to avoid others that are viewed as "contaminated" to the observer. This happens due to the fact of the observer viewing something that is seen as bad or to seek objects that have been associated with what seems good. Some things one can view as harmful can tend not to really be. This sometimes leads to irrational thinking on behalf of the observer.

• Default Heuristic — In real world models it is common for consumers to apply this heuristic when selecting the default option regardless of whether the option was their preference.

• Educated Guess Heuristic — When an individual responds to a decision using relevant information they have stored relating to the problem.

• Effort heuristic — the worth of an object is determined by the amount of effort put into the production of the object. Objects that took longer to produce are more valuable while the objects that took less time are deemed not as valuable. Also applies to how much effort is put into achieving the product. This can be seen as the difference of working and earning the object versus finding the object on the side of the street. It can be the same object but the one found will not be deemed as valuable as the one that we earned.

• Escalation of commitment — Describes the phenomenon where people justify increased investment in a decision, based on the cumulative prior investment, despite new evidence suggesting that the cost, starting today, of continuing the decision outweighs the expected benefit. This is related to the sunk cost fallacy.

• Fairness Heuristic — Applies to the reaction of an individual to a decision from an authoritative figure. If the decision is enacted in a fair manner the likelihood of the individual to comply voluntarily is higher than if it is unfair.

• Familiarity heuristic — A mental shortcut applied to various situations in which individuals assume that the circumstances underlying the past behavior still hold true for the present situation and that the past behavior thus can be correctly applied to the new situation. Especially prevalent when the individual experiences a high cognitive load.

• Naïve diversification — When asked to make several choices at once, people tend to diversify more than when making the same type of decision sequentially.
• Peak–end rule — a person's subjective perceptions during the most intense and final moments of an event are averaged together into a single judgment. For example, a person might judge the difficulty of a workout by taking into consideration only the most demanding part of the workout (e.g., Tabata sprints) and what happens at the very end (e.g., a cool-down). In this way, a difficult workout such as the one described here could be perceived as "easier" than a more relaxed workout that did not vary in intensity (e.g., 45 minutes of cycling in aerobic zone 3, without cool-down).

• Representativeness heuristic — A mental shortcut used when making judgements about the probability of an event under uncertainty. Or, judging a situation based on how similar the prospects are to the prototypes the person holds in his or her mind. For example, in a 1982 Tversky and Kahneman experiment, participants were given a description of a woman named Linda. Based on the description, it was likely that Linda was a feminist. Eighty to ninety percent of participants, choosing from two options, chose that it was more likely for Linda to be a feminist and a bank teller than only a bank teller. The likelihood of two events cannot be greater than that of either of the two events individually. For this reason, the representativeness heuristic is exemplary of the conjunction fallacy.

• Scarcity heuristic — As in economics, the scarcer an object or event is, the more value is attributed to the object or event. The lack of abundance is an indicator of value and provides a mental shortcut that influences the subjective valuation based on how easily the thing might be replaced or lost to competitors. The scarcity heuristic is a cognitive rule that the more difficult it is to acquire an item, the more value that item must have. In many situations we use an item’s availability, its perceived abundance, to quickly estimate quality and/or utility. This can lead to systematic judgement errors or cognitive bias.

• Simulation heuristic — simplified mental strategy in which people determine the likelihood of an event happening based on how easy it is to mentally picture the event happening. People regret the events that are easier to imagine over the ones that would be harder to. It is also thought that people will use this heuristic to predict the likelihood of another's behavior happening. This shows that people are constantly simulating everything around them in order to be able to predict the likelihood of events around them. It is believed that people do this by mentally undoing events that they have experienced and then running mental simulations of the events with the corresponding input values of the altered model.

• Social proof — also known as the informational social influence which was named by Robert Cialdini in his 1984 book Influence. It is where people copy the actions of others. It is more prominent when people are uncertain how to behave, especially in ambiguous social situations.

• Working Backward Heuristic — When an individual assumes they have already solved a problem they work backwards in order to find how to achieve the solution they originally figured out.

Formal models of heuristics

• Elimination by Aspects heuristic
• Fast-and-frugal trees
• Fluency heuristic
• Gaze heuristic
• Recognition heuristic
• Satisficing
• Similarity heuristic
• Take-the-best heuristic

Cognitive maps

Heuristics were also found to be used in the manipulation and creation of cognitive maps. Cognitive maps are internal representations of our physical environment, particularly associated with spatial relationships. These internal representations are used by our memory as a guide in our external environment. It was found that when questioned about maps imaging, distancing, etc., people commonly made distortions to images. These distortions took shape in the regularisation of images (i.e., images are represented as more like pure abstract geometric images, though they are irregular in shape).

There are several ways that humans form and use cognitive maps, with visual intake being an especially key part of mapping: the first is by using landmarks, whereby a person uses a mental image to estimate a relationship, usually distance, between two objects. The second is route-road knowledge, and is generally developed after a person has performed a task and is relaying the information of that task to another person. The third is a survey, whereby a person estimates a distance based on a mental image that, to them, might appear like an actual map. This image is generally created when a person's brain begins making image corrections. These are presented in five ways:

1. Right-angle bias: when a person straightens out an image, like mapping an intersection, and begins to give everything 90-degree angles, when in reality it may not be that way.
2. Symmetry heuristic: when people tend to think of shapes, or buildings, as being more symmetrical than they really are.
3. Rotation heuristic: when a person takes a naturally (realistically) distorted image and straightens it out for their mental image.
4. Alignment heuristic: similar to the previous, where people align objects mentally to make them straighter than they really are.
5. Relative-position heuristic: people do not accurately distance landmarks in their mental image based on how well they remember them.

Another method of creating cognitive maps is by means of auditory intake based on verbal descriptions. Using the mapping based from a person's visual intake, another person can create a mental image, such as directions to a certain location.

See also: Intuition and decision-making § Heuristics, and Heuristic-systematic model of information processing

Philosophy

A heuristic device is used when an entity X exists to enable understanding of, or knowledge concerning, some other entity Y.

A good example is a model that, as it is never identical with what it models, is a heuristic device to enable understanding of what it models. Stories, metaphors, etc., can also be termed heuristic in this sense. A classic example is the notion of utopia as described in Plato's best-known work, The Republic. This means that the "ideal city" as depicted in The Republic is not given as something to be pursued, or to present an orientation-point for development. Rather, it shows how things would have to be connected, and how one thing would lead to another (often with highly problematic results), if one opted for certain principles and carried them through rigorously.

Heuristic is also often used as a noun to describe a rule-of-thumb, procedure, or method. Philosophers of science have emphasised the importance of heuristics in creative thought and the construction of scientific theories. (See The Logic of Scientific Discovery by Karl Popper; and philosophers such as Imre Lakatos, Lindley Darden, William C. Wimsatt and others.)

Law

In legal theory, especially in the theory of law and economics, heuristics are used in the law when case-by-case analysis would be impractical, insofar as "practicality" is defined by the interests of a governing body.

The present securities regulation regime largely assumes that all investors act as perfectly rational persons. In truth, actual investors face cognitive limitations from biases, heuristics, and framing effects. For instance, in all states in the United States the legal drinking age for unsupervised persons is 21 years, because it is argued that people need to be mature enough to make decisions involving the risks of alcohol consumption. However, assuming people mature at different rates, the specific age of 21 would be too late for some and too early for others. In this case, the somewhat arbitrary deadline is used because it is impossible or impractical to tell whether an individual is sufficiently mature for society to trust them with that kind of responsibility. Some proposed changes, however, have included the completion of an alcohol education course rather than the attainment of 21 years of age as the criterion for legal alcohol possession. This would put youth alcohol policy more on a case-by-case basis and less on a heuristic one, since the completion of such a course would presumably be voluntary and not uniform across the population.

The same reasoning applies to patent law. Patents are justified on the grounds that inventors must be protected so they have incentive to invent. It is therefore argued that it is in society's best interest that inventors receive a temporary government-granted monopoly on their idea, so that they can recoup investment costs and make economic profit for a limited period. In the United States, the length of this temporary monopoly is 20 years from the date the patent application was filed, though the monopoly does not actually begin until the application has matured into a patent. However, like the drinking-age problem above, the specific length of time would need to be different for every product to be efficient. A 20-year term is used because it is difficult to tell what the number should be for any individual patent. More recently, some, including University of North Dakota law professor Eric E. Johnson, have argued that patents in different kinds of industries – such as software patents – should be protected for different lengths of time.

Stereotyping

Stereotyping is a type of heuristic that people use to form opinions or make judgements about things they have never seen or experienced. They work as a mental shortcut to assess everything from the social status of a person (based on their actions), to whether a plant is a tree based on the assumption that it is tall, has a trunk and has leaves (even though the person making the evaluation might never have seen that particular type of tree before).

Stereotypes, as first described by journalist Walter Lippmann in his book Public Opinion (1922), are the pictures we have in our heads that are built around experiences as well as what we are told about the world.

Artificial intelligence

A heuristic can be used in artificial intelligence systems while searching a solution space. The heuristic is derived by using some function that is put into the system by the designer, or by adjusting the weight of branches based on how likely each branch is to lead to a goal node.

See also: Heuristic (computer science) and Heuristic evaluation

Closure (psychology)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Closure_(psychology)

Closure or need for closure (NFC) (used interchangeably with need for cognitive closure (NFCC)) are social psychological terms that describe an individual's desire for a clear, firm answer to a question and an aversion toward ambiguity. 

The term "need" denotes a motivated tendency to seek out information. The need for closure is the motivation to find an answer to an ambiguous situation. This motivation is enhanced by the perceived benefits of obtaining closure, such as the increased ability to predict the world and a stronger basis for action. This motivation is also enhanced by the perceived costs of lacking closure, such as dealing with uncertainty. A sense of closure is not usually possible with ambiguous loss, such as a missing person, and the hoped-for benefits, such as a sense of relief after the death of a person who inflicted harm, are not necessarily obtained. Because of this mismatch between what individuals hope will happen if they achieve closure and what they actually experience, the idea of getting closure has been described as a myth.

The level of the need for cognitive closure is a fairly stable individual characteristic. It can affect what information individuals seek out and how they process it. This need can be affected by situational factors. For example, in the presence of circumstances that increase the need for closure, individuals are more likely to use simple cognitive structures to process information.

According to Kruglanski et al., need for closure exerts its effects via two general tendencies: the urgency tendency (the inclination to attain closure as quickly as possible) and the permanence tendency (the tendency to maintain it for as long as possible). Together, these tendencies may produce the inclinations to seize and then freeze on early judgmental cues, reducing the extent of information processing and hypothesis generation and introducing biases in thinking.

Need for Closure Scale

The need for closure in social psychology is thought to be a fairly stable dispositional characteristic that can, nonetheless, be affected by situational factors. The Need for Closure Scale (NFCS) was developed by Arie Kruglanski, Donna Webster, and Adena Klem in 1993 and is designed to operationalize this construct and is presented as a unidimensional instrument possessing strong discriminant and predictive validity.

People who score high on the need for closure scale are more likely to exhibit impression primacy effects to correspondence bias, make stereotypical judgments, assimilate new information to existing, active beliefs, and, in the presence of prior information, resist persuasion. Someone rating low on need for closure will express more ideational fluidity and creative acts. Items on the scale include statements such as "I think that having clear rules and order at work is essential to success," and "I do not like situations that are uncertain." Items such as "Even after I've made up my mind about something, I am always eager to consider a different opinion," and "I like to have friends who are unpredictable" are reverse scored.

Composed of 42 items, the scale has been used in numerous research studies and has been translated into multiple languages. Although Webster and Kruglanski (1994) treated the Need for Closure Scale as unidimensional (i.e., as measuring a single factor), the scale actually contains two orthogonal factors, decisiveness and need for structure. Thus, using a total scale score can overlook effects for each factor and complicate interpretations. In 2007, Roets and Van Hiel tried to resolve this issue by revising the scale so it would measure only one thing. They came up with a set of new decisiveness items that provided a viable alternative for the old Decisiveness subscale of the NFCS, which was poorly related to the other NFCS facet scales and had questionable validity. The new items were developed with explicit reference to decisiveness but formulated in such a way that they relate to the need rather than to the ability to decide. In 2011, Roets and Van Hiel created an abridged and empirically validated NFC scale consisting of only 15 items from the original NFC.

NFCS items correlate positively with authoritarianism, intolerance of ambiguity, dogmatism, need for order and structure and negatively with cognitive complexity and impulsivity, among several other cognitive tools and personality traits.

High NFC scores consistently correlate with items on the C-Scale (conservatism) as well as other measures of political and social conservatism.

Need to avoid

Main article: Need for cognition

Functionally opposite to the need for closure is the need to avoid closure. Need to avoid closure reflects the desire to suspend judgmental commitment. It also contains the subcategories specific and non-specific need to avoid closure. Avoidance of specific closure reflects the desire to avoid specific answers to one's questions. The non-specific need to avoid closure is much like the need for closure irrespective of whether or not this new knowledge points to a conclusion having positive or negative implications for them.

The need to avoid closure may stem from the perceived costs of possessing closure (e.g., envisioned penalties for an erroneous closure or perceived drawbacks of actions implied by closure) and the perceived benefits of lacking closure (e.g., immunity from possible criticism of any given closure). The need to avoid closure is controlled by the desire to avoid negative consequences of achieving closure of a situation or to continue the benefits of not closing but elongating a situation.

The need and avoidance of closure are conceptualized as ends of a continuum ranging from strong strivings for closure to strong resistance of closure. This is applied in the NFC Scale.

Lack of

The lack of closure leaves a situation in ambiguity. People high in need for closure seek to avoid this ambiguity at all costs where people high in need to avoid closure strive to make situations more ambiguous. Some perceived benefits of cognitive closure may relate to predictability, the basis for action, or social status accorded the possessors of knowledge (i.e., "experts"). Similarly, some perceived costs of lacking closure may relate to the additional time and effort required to attain closure, or the unpleasantness of process whereby closure must be reached. Occasionally, however, lack of closure maybe perceived to offer various advantages such as freedom from a constraining commitment, neutrality in an acrimonious dispute, the maintenance of a romantic mystery and so on. Though lack of closure is generally thought of as being negative, it is clear that closure and lack of closure have positive or negative implications depending on the person and situation surrounding them.

Implications

A need for cognitive closure may occur while engaged in goal-driven or goal-motivated cognitive functions (e.g., attention control, memory recall, information selection and processing, cognitive inhibition, etc.). Ideally, people should attempt to acquire new knowledge to satisfy questions regarding particular issues (specific cognitive closure) irrespective of whether that knowledge points to a conclusion having positive or negative implications for them (non-specific cognitive closure). But because urgency and permanence are central to the motivational core of this overall process, individuals (or groups) may be compelled, consciously or unconsciously, to obtain information prematurely and irrespective of content.

A high need for cognitive closure might then invite bias in:

1. selecting the most relevant information one should attend to for increasing chances of adaptation
2. initiating and sustaining cognitive manipulations that are required to achieve particular outcomes
3. making judgments and assessments of input information
4. weighing information during the course of decision-making

For example, the level of NFCC can influence decision-making strategies used by an individual. In a study by Choi et al. that manipulated NFCC, the authors found that a higher NFCC was associated with a preference for using the faster "attribute-based search" which involves examining all available alternatives on one attribute and then moving on to the next attribute. Individuals with a lower NFCC, in contrast, used the "alternative-based search", such that they examine all attributes of one alternative, then move on to the next alternative. Thus, studying NFCC has huge implications for consumer buying behavior.

Need for closure has also been found to have a role in race- and gender-based prejudice. Roets describes a conceptual fit between Allport's "motivated cognitive style" of individuals who exhibit prejudice and Kruglanksi and Webster's concept of high-NFCC individuals, such that both display urgency tendency i.e. the desire for quick, definite answers and permanence tendency i.e., the perseverance of the obtained answer in spite of contradictory information. Thus, NFC provides a strong empirical base for Allport's hypothesized underlying cognitive style of prejudiced individuals.

A high need also induces the tendency to form knowledge more quickly, tying into other concepts, such as a tendency to prefer autocracy i.e. "hard" forms of influence that motivate the targets to comply with the agents' demands quickly via the promise of positive consequences or the threat of negative consequences, rather than "soft" forms of influence that might use extended argumentation or persuasion.

Additionally, and especially in those with strong needs for certainty (as measured on NFC Scale), the impulse to achieve cognitive closure may sometimes produce or evoke a mood instability, and/or truncated perceptions of one's available behavioral choices, should some newly acquired information challenge preconceptions that they had long considered to be certain, permanent and inviolate e.g. certain religious or ethical views and values.

Thus it is apparent that the need for cognitive closure may have important implications for both personal and inter-personal thoughts and actions, including some related to educational processes and school learning.

In education

Formal education environments, such as elementary and secondary schools, present opportunities for learners to acquire new knowledge and skills, and to achieve deep, domain-specific conceptual mastery which, through well-designed pedagogical guidance and academic study, may enhance future career readiness, civic engagement, and general well-being. However, although it is understood that the basic principles of learning assert the importance of attending to students’ prior knowledge, fostering conceptual understanding, and cultivating metacognitive awareness, students must also become engaged and be willing to tolerate and cognitively work through the intellectual ambiguity often associated with exposure to novel information and tasks.

Yet for students who have high need for cognitive closure, this phenomenon may inadvertently lead to the inhibition of cognitive functions and processes essential to the learning process, so that they can maintain their prior certainty and/or perceived permanence of personally or socially important ideas, even if those ideas or knowledge are distinctly unrelated to any specific content or information being presented in the classroom. In instances such as these, an individual's desire for cognitive closure in another area may outweigh her/his motivation to expend cognitive resources toward learning new information. As a result, the student may appear uninterested and susceptible to under-achieving e.g. poor grades or not performing to expected levels.

Unfortunately, in the absence of understanding and consideration of how need for cognitive closure may influence academic and/or achievement motivation, educators may erroneously conclude that a student does not have a desire to learn or that she/he has a cognitive, psychological, intellectual, or behavioral deficiency that is impeding the learning process. This is not to suggest that need for cognitive closure is a suitable explanation for all learning problems; however, in working with students who appear to be experiencing learning challenges manifested through amotivation or low motivation, it would not be unreasonable to explore need for cognitive closure as a potential factor.

Research

Individuals scoring high on the NFCS are more likely to attempt to draw closure by relying on incipient cues, and the first-encountered apparent fit. The need for closure is also said to predispose a very narrow or shallow information search, along with a higher tendency to use cognitive heuristics, when seeking solutions. (Van Hiel and Mervielde, 2003)

In studies on creativity, individuals with high need-for-closure ratings had low creativity scores. Those low in need-for-closure more frequently produced novel solutions that motivated and inspired others in their groups, and the outcomes of the projects in which they participated were rated as correspondingly more productive.

Most research on the need for closure has investigated its relation to social stimuli. However, recent research suggests that it may also predict responses to non-social stimuli. In particular, the need for closure predicts an evaluative bias against deviant non-social stimuli (e.g., the letter "A" presented in a category of letter "B"s)

"Closure" has also been used more loosely to refer to the outcome of an experience which, by virtue of its completion, demonstrates a therapeutic value. Legal scholars have linked "closure" to "catharsis" and "satisfaction" and at times the legal system may be enlisted into an individual's desire for the cessation of uncertainty. In the case of the death penalty, for example, victims seeking "closure" may adopt effective strategies as diverse as retribution, on one hand, and forgiveness on the other.

Exposure therapy

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Exposure_therapy 

Exposure therapy is a technique in behavior therapy to treat anxiety disorders. Exposure therapy involves exposing the target patient to the anxiety source or its context without the intention to cause any danger. Doing so is thought to help them overcome their anxiety or distress. Procedurally, it is similar to the fear extinction paradigm developed for studying laboratory rodents. Numerous studies have demonstrated its effectiveness in the treatment of disorders such as generalized anxiety disorder, social anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder (PTSD), and specific phobias.

Medical uses

Generalized anxiety disorder

There is empirical evidence that exposure therapy can be an effective treatment for people with generalized anxiety disorder, citing specifically in vivo exposure therapy, (exposure through a real life situation), which has greater effectiveness than imaginal exposure in regards to generalized anxiety disorder. The aim of in vivo exposure treatment is to promote emotional regulation using systematic and controlled therapeutic exposure to traumatic stimuli. Exposure therapy is also a preferred method for children who struggle with anxiety.

Phobia

Exposure therapy is the most successful known treatment for phobias. Several published meta-analyses included studies of one-to-three hour single-session treatments of phobias, using imaginal exposure. At a post-treatment follow-up four years later 90% of people retained a considerable reduction in fear, avoidance, and overall level of impairment, while 65% no longer experienced any symptoms of a specific phobia.

Agoraphobia and social anxiety disorder are examples of phobias that have been successfully treated by exposure therapy.

Post-traumatic stress disorder

Exposure therapy in PTSD involves exposing the patient to PTSD-anxiety triggering stimuli, with the aim of weakening the neural connections between triggers and trauma memories (aka desensitisation). Exposure may involve:

• a real life trigger ("in vivo")
• an imagined trigger ("imaginal")
• Virtual reality exposure
• a triggered feeling generated in a physical way ("interoceptive").

Forms include:

• Flooding – exposing the patient directly to a triggering stimulus, while simultaneously making them not feel afraid.
• Systematic desensitisation (aka "graduated exposure") – gradually exposing the patient to increasingly vivid experiences that are related to the trauma, but do not trigger post-traumatic stress.
• Narrative exposure therapy - creates a written account of the traumatic experiences of a patient or group of patients, in a way that serves to recapture their self-respect and acknowledges their value. Under this name it is used mainly with refugees, in groups. It also forms an important part of cognitive processing therapy and is conditionally recommended for treatment of PTSD by the American Psychological Association.
• Prolonged exposure therapy (PE) - a form of behavior therapy and cognitive behavioral therapy designed to treat post-traumatic stress disorder, characterized by two main treatment procedures – imaginal and in vivo exposures. Imaginal exposure is repeated 'on-purpose' retelling of the trauma memory. In vivo exposure is gradually confronting situations, places, and things that are reminders of the trauma or feel dangerous (despite being objectively safe). Additional procedures include processing of the trauma memory and breathing retraining. The American Psychological Association strongly recommends PE as a first-line psychotherapy treatment for PTSD.

Researchers began experimenting with Virtual reality exposure (VRE) therapy in PTSD exposure therapy in 1997 with the advent of the "Virtual Vietnam" scenario. Virtual Vietnam was used as a graduated exposure therapy treatment for Vietnam veterans meeting the qualification criteria for PTSD. A 50-year-old Caucasian male was the first veteran studied. The preliminary results concluded improvement post-treatment across all measures of PTSD and maintenance of the gains at the six-month follow up. Subsequent open clinical trial of Virtual Vietnam using 16 veterans, showed a reduction in PTSD symptoms.

This method was also tested on several active duty Army soldiers, using an immersive computer simulation of military settings over six sessions. Self-reported PTSD symptoms of these soldiers were greatly diminished following the treatment. Exposure therapy has shown promise in the treatment of co-morbid PTSD and substance abuse.

Obsessive compulsive disorder

Exposure and response prevention (also known as exposure and ritual prevention; ERP or EX/RP) is a variant of exposure therapy that is recommended by the American Academy of Child and Adolescent Psychiatry (AACAP), the American Psychiatric Association (APA), and the Mayo Clinic as first-line treatment of obsessive compulsive disorder (OCD) citing that it has the richest empirical support for both youth and adolescent outcomes.

ERP is predicated on the idea that a therapeutic effect is achieved as subjects confront their fears, but refrain from engaging in the escape response or ritual that delays or eliminates distress. In the case of individuals with OCD or an anxiety disorder, there is a thought or situation that causes distress. Individuals usually combat this distress through specific behaviors that include avoidance or rituals. However, ERP involves purposefully evoking fear, anxiety, and or distress in the individual by exposing him/her to the feared stimulus. The response prevention then involves having the individual refrain from the ritualistic or otherwise compulsive behavior that functions to decrease distress. The patient is then taught to tolerate distress until it fades away on its own, thereby learning that rituals are not always necessary to decrease distress or anxiety. Over repeated practice of ERP, patients with OCD expect to find that they can have obsessive thoughts and images but not have the need to engage in compulsive rituals to decrease distress.

The AACAP's practice parameters for OCD recommends cognitive behavioral therapy, and more specifically ERP, as first line treatment for youth with mild to moderate severity OCD and combination psychotherapy and pharmacotherapy for severe OCD. The Cochrane Review's examinations of different randomized control trials echoes repeated findings of the superiority of ERP over waitlist control or pill-placebos, the superiority of combination ERP and pharmacotherapy, but similar effect sizes of efficacy between ERP or pharmacotherapy alone.

Techniques

Exposure therapy is based on the principle of respondent conditioning often termed Pavlovian extinction. The exposure therapist identifies the cognitions, emotions and physiological arousal that accompany a fear-inducing stimulus and then tries to break the pattern of escape that maintains the fear. This is done by exposing the patient to progressively stronger fear-inducing stimuli. Fear is minimized at each of a series of steadily escalating steps or challenges (a hierarchy), which can be explicit ("static") or implicit ("dynamic" — see Method of Factors) until the fear is finally gone. The patient is able to terminate the procedure at any time.

There are three types of exposure procedures. The first is in vivo or "real life." This type exposes the patient to actual fear-inducing situations. For example, if someone fears public speaking, the person may be asked to give a speech to a small group of people. The second type of exposure is imaginal, where patients are asked to imagine a situation that they are afraid of. This procedure is helpful for people who need to confront feared thoughts and memories. The third type of exposure is interoceptive, which may be used for more specific disorders such as panic or post-traumatic stress disorder. Patients confront feared bodily symptoms such as increased heart rate and shortness of breath. All types of exposure may be used together or separately.

While evidence clearly supports the effectiveness of exposure therapy, some clinicians are uncomfortable using imaginal exposure therapy, especially in cases of PTSD. They may not understand it, are not confident in their own ability to use it, or more commonly, they see significant contraindications for their client.

Flooding therapy also exposes the patient to feared stimuli, but it is quite distinct in that flooding starts at the most feared item in a fear hierarchy, while exposure starts at the least fear-inducing.

Exposure and response prevention

In the exposure and response prevention (ERP or EX/RP) variation of exposure therapy, the resolution to refrain from the escape response is to be maintained at all times and not just during specific practice sessions. Thus, not only does the subject experience habituation to the feared stimulus, but they also practice a fear-incompatible behavioral response to the stimulus. The distinctive feature is that individuals confront their fears and discontinue their escape response. The American Psychiatric Association recommends ERP for the treatment of OCD, citing that ERP has the richest empirical support.

While this type of therapy typically causes some short-term anxiety, this facilitates long-term reduction in obsessive and compulsive symptoms. Generally, ERP incorporates a relapse prevention plan toward the end of the course of therapy.

History

The use of exposure as a mode of therapy began in the 1950s, at a time when psychodynamic views dominated Western clinical practice and behavioral therapy was first emerging. South African psychologists and psychiatrists first used exposure as a way to reduce pathological fears, such as phobias and anxiety-related problems, and they brought their methods to England in the Maudsley Hospital training program.

Joseph Wolpe (1915–1997) was one of the first psychiatrists to spark interest in treating psychiatric problems as behavioral issues. He sought consultation with other behavioral psychologists, among them James G. Taylor (1897–1973), who worked in the psychology department of the University of Cape Town in South Africa. Although most of his work went unpublished, Taylor was the first psychologist known to use exposure therapy treatment for anxiety, including methods of situational exposure with response prevention—a common exposure therapy technique still being used. Since the 1950s, several sorts of exposure therapy have been developed, including systematic desensitization, flooding, implosive therapy, prolonged exposure therapy, in vivo exposure therapy, and imaginal exposure therapy.

Mindfulness

A 2015 review pointed out parallels between exposure therapy and mindfulness, stating that mindful meditation "resembles an exposure situation because [mindfulness] practitioners 'turn towards their emotional experience', bring acceptance to bodily and affective responses, and refrain from engaging in internal reactivity towards it." Imaging studies have shown that the ventromedial prefrontal cortex, hippocampus, and the amygdala are all affected by exposure therapy; imaging studies have shown similar activity in these regions with mindfulness training.

EMDR

Eye movement desensitization and reprocessing (EMDR) includes an element of exposure therapy (desensitization), though whether this is an effective method or not, is controversial.

Research

Exposure therapy can be investigated in the laboratory using Pavlovian extinction paradigms. Using rodents such as rats or mice to study extinction allows for the investigation of underlying neurobiological mechanisms involved, as well as testing of pharmacological adjuncts to improve extinction learning.